Many devices exist in which a component must be positioned with extreme accuracy and the position adjusted from time to time. Such a component, for example, is a boring cartridge that is mounted on a boring tool. Screw mechanisms, such as differential screws or compound screws, are conventionally used to provide fine adjustment of the cutting insert to compensate for wear of the insert. By definition, a compound screw is a screw having on the same axis two or more screws with different pitch, or running in different directions (a right and left screw), and a differential screw is a compound screw by which a motion is produced equal to the difference of the motions of the component screws. The difficulty with conventional screw mechanisms, however, is that when presented with a bore that has tolerance limits in the range of plus or minus 0.0002 to 0.0030 inches, most products are limited to a single bore per tool and/or can be fairly expensive.
Thus, there is a need to provide a boring cartridge that includes both axial and radial micro-adjustable screw assemblies that provide fine adjustment of the cutting insert in both the axial and radial directions, while capable of being used in a boring bar with a diameter that is substantially smaller than conventional boring bars having generally similar cutting insert mountings.